1. Field
A binder for a rechargeable lithium battery, an electrode for a rechargeable lithium battery, a method of preparing the electrode for the rechargeable lithium battery, and a rechargeable lithium battery including the electrode are disclosed.
2. Description of the Related Art
A rechargeable lithium battery includes positive and negative electrodes including a material that can reversibly intercalate/deintercalate lithium ions as positive and negative active materials and an organic electrolyte solution or a polymer electrolyte solution charged between the positive and negative electrodes. Herein, the positive and negative electrodes intercalate and deintercalate lithium ions and produce electrical energy through oxidation and reduction reactions.
As for a positive active material for a lithium rechargeable battery, a lithium-transition metal oxide being capable of intercalating and deintercalating lithium, such as LiCoO2, LiMn2O4, LiNi1-xCoxO2 (0<x<1), and the like, has been used.
As for a negative active material for a lithium rechargeable battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon capable of intercalating and deintercalating lithium ions have been used. Recently, demand of a battery having high energy density has increasingly required a negative active material having high theoretical capacity density. Accordingly, Si, Sn, and Ge alloyed with lithium and an oxide thereof and an alloy thereof have drawn attention. In particular, a Si-based negative active material has very high charge capacity and is widely applied to a high-capacity battery. However, the Si-based negative active material may expand by about 300% to about 400% during charge and discharge. Accordingly, research on a binder capable of effectively suppressing expansion of the Si-based negative active material and/or being more durable with respect to the expansion, is actively performed.